textproduct: Rapid City

KEY MESSAGES

- Hot Tuesday with chances for severe storms.

- Cooler Wednesday and Thursday

- Near daily chances for at least isolated showers/storms through the week.

DISCUSSION

(This Evening Through Monday) Issued at 1256 PM MDT Mon Jun 8 2026

Current upper air models show upper low centered over AB/SK border, with upper ridge over the Great Lakes, and southwest flow over the forecast area. Surface analysis shows high pressure over the WY/SD border. Radar and Satellite show mostly clear skies, with some isolated showers over northwestern SD this afternoon. Winds are transitioning to the southeast as the high slides eastward, while temperatures currently sit in the 60s to low 70s.

Aside from these few isolated showers/storms this afternoon through tonight, expect most areas to remain dry. Tuesday is expected to be hotter, as low level WAA sets in, bringing highs from the mid 80s to nearing 100 Tuesday afternoon, with the warmest temperatures expected in the western SD plains. Main concern for Tuesday will be increasing chances for storms throughout the day. Plenty of available energy Tuesday, with models showing CAPE values ranging from 2500-3500 j/Kg for areas east of the Black Hills. With steepening lapse rates (8-9 c/km) and 0-6km shear in the 35-45kt range, some severe storms may be possible. Currently CAMS show some potential for isolated supercell development late afternoon, but severe chances increase later as LLJ increases and models show storm mode switching to more linear storms forming along the frontal boundary as it moves through. Timing will be important, as currently models show isolated storms developing around 3pm MDT and over the next couple hours forming along the front, however by then models have the boundary almost out of our area. This should limit the severe threat to areas east of the Black Hills closer towards central SD. Some of our western SD plains are in a marginal to slight risk for severe storms, while the enhanced risk remains just east of our forecast area.

Following this cold front, low level northwest flow will usher in a bit cooler temperatures for Wednesday and Thursday, with highs ranging from the mid 60s to low 80s. Chances for isolated to scattered showers/storms will continue mid-week as a weak wave moves through Wednesday, and slightly strong wave on Thursday, though currently severe storms are not expected those days. By Friday, the upper low now sits over Ontario, with a more quasi- zonal flow over the forecast area and brief break from isolated precipitation. Models do show another disturbance moving through over the weekend, bringing precipitation chances back later Saturday into Sunday.

AVIATION

(For the 00Z TAFS Through 00Z Tuesday Evening) Issued At 537 PM MDT Mon Jun 8 2026

VFR conditions are expected throughout the forecast period. Showers and thunderstorms are expected Tuesday afternoon (mainly western SD) and will push eastward through the evening. Southerly winds will continue overnight, then become southwesterly through the day Tuesday.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.